On Thu, Mar 19, 2020 at 11:43:20AM -0700, Andy Lutomirski wrote:

Or future generations could have enough hardware support for debugging
that #DB doesn't need to be intercepted or can be re-injected
correctly with the #DB vector.

Yeah, the problem is, the GHCB spec suggests the single-step-over-iret
way to re-enable the NMI window and requires intercepting #DB for it. So
the hypervisor probably still has to intercept it, even when debug
support is added some day. I need to think more about this.

Regards,

	Joerg